The record-breaking low point came in a poll for STV which showed 57 per cent saying they will back the SNP with their constituency vote at the Holyrood elections in 2016, with just 23 per cent planning to vote Labour.

And 50 per cent of voters said they would back the SNP in the second vote, for the regional lists.

That would result in the SNP taking an overwhelming 75 out of the Scottish Parliament’s 129 seats, up from the overall majority of 69 they won in 2011.

Labour would lose six of the 37 seats they won at that election.

The poll also predicts the Scottish Tory contingent at Holyrood would be slashed from 15 to just seven.

Pollsters Ipsos Mori say the poll is in line with findings last week when 52 per cent said they would vote SNP in the UK general election next May, a pattern which could leave Labour almost wiped out with just four Scottish MPs.

That survey also showed Labour polling 23 per cent of the Scottish vote. In comparison, the support for the SNP would give them a projected 54 seats at Westminster.

The Liberal Democrats would have one MP and the Conservative party would be left without any.

Those days are over for Scottish Labour. This is a fresh start

Jim Murphy

At the 2010 general election, Labour won 42 per cent of the Scottish vote and the SNP just 19.9 per cent.

At the last Holyrood elections, Alex Salmond won an outright majority with 45 per cent of the votes cast and these results suggest the Labour collapse would be even greater next time.

The results came as nominations for the Scottish Labour leadership elections closed yesterday and front runner Jim Murphy said his broad support from politicians at Holyrood, Westminster and in Europe proved he is “a unifying figure to bring the Scottish Labour Party together again”.

He said: “In the past the Scottish Labour Party has seemed like a team that enjoyed tackling its own players in public.

“If a football team did that the supporters would soon turn away and the team would end up playing in an empty stadium.

“Those days are over for Scottish Labour. This is a fresh start.”

But Mark Diffley, director at Ipsos MORI Scotland, said: “These figures represent both a high point for the SNP and a low point for Scottish Labour in terms of polls we have undertaken.

“It also underlines the tough challenge faced by Labour’s new Scottish leader in the months ahead in winning back some of the lost ground.”